New heterocyclic paraquinones



United States Patent 2,938,903 NEW HETEROCYCLIC PARAQUIN ONES Richard J. Boyle, Neshanic, N.J., assignor to American 'Cyanamid Company, New York, N.Y., a corporation of Maine No Drawing. Filed Apr. 4, 1958, Ser. No. 726,345 11 Claims. (Cl. 260-2564) This invention relates to new quinones, and more specifically, it relates to new 1,4-quinones of a heterocyclic ring system represented by the following formula:

0 H (/rii) U (its) 8 structure:

0 H Y /N\ N K) or a trans compound of the structure:

or mixtures of the two. From various properties of the products, I believe that there is formed principally the trans isomer, and the compounds will be given this structure in the discussion and the examples given below. This structure is named (for the pyridine derivative) as a 6,13-di0ne of 6(H), l3(H)-dipyrido[1,2'- a,1",2"-a] benzo [1,2-d,4,5-d] bis-imidazole, or in more abbreviated fashion, as quinone-bis-pyridoimidazole.

The compounds of my invention are new colored compounds which may be used as vat dyes in the ordinary manner. They are prepared by the treatment of a 2- amino-pyridine, quinoline or pyrimidine with chloranil (2,3,5,6-tetrachloro-para-benzoquinone) by heating the reactants in an organic solvent. Suitable organic solvents include such solvents as ethanol, methanol, Cellosolve, and the like.

Substituents are introduced into the new quinones of my invention by the use of the properly substituted 2- aminopyridine, quinoline or pyrimidine. Examples of the 2-aminopyridines, quinolines, and pyrimidines which may be used in the preparation of these new quinones, are:

Z-aminopyridine 2-amino-3-methylpyridine 2-amino-4-methylpyridine Z-amino-S-methylpyridine 2-amino-6-methylpyridine Z-amino-S-chloropyridine 2-amino-4,6-dimethylpyridine 2-amino-5-nitropyridine 2-amino-3-bromopyridine 2-amino-4-bromopyridine Z-amino-S-bromopyridine 2-amino-6-chloropyridine 2-amino-3-chloro-S-nitropyridine 2-amino-3,4-dibromopyridine 2-amino-3,5-dibromopyridine Z-amino-S-iodopyridine 2-amino-S-bromo-3-nitropyridine 2-amino-6-chloro-3 -phenylpyridine 2-amino-4-ethylpyridine 2-amino-6-bromopyridine Z-amino-S-iodopyridine 2-amino-4-iodopyridine 2-amino-6-ethoxypyridine Z-amino-S-ethoxypyridine 2-amino-3,5-dinitropyridine 2-amino-3,5-dichloropyridine 2-amino-3,4-dichloropyridine 2-amino4-chl0ropyridine 2-amino-3-chloropyridine 2-amino-3,S-diiodopyridine 2-aminoquinoline 2-amino-8-ethoxyquinoline 2-amino-3-phenylquinoline Z-amino-S-methylquinoline 2-amino-8-methylquino1ine 2-amino-6-methoxy-3-phenylquinoline Z-amino-8-methoxy-3-phenylquinoline Z-aminopyrimidine 2-amino-4-methylpyrimidine 2-amino-4-isobutylpyrimidine 2-amino-4-ethylpyrimidine 2-amino-4-ethoxypyrimidine 2-arnino-4-amylpyrimidine 2-amino-4-methyl-5-amylpyrimidine 2-amino-4-chloropyrimidine 2-amino-4-butylpyrimidine 2-amino-4-t-butylpyrimidine Z-amino-S-chloropyrimidine 2-amino-5-chloro-4,G-dimethylpyrimidine 2-amino-6-ethoxypyrimidine 2-arnino-6-ethylpyrimidine 2-amino-4,6-diethylpyrimidine 2-arnino-4,6-diiodopyrimidine 2-amino-4-methoxypyrimidine 2-amino-4-hexylpyrimidine 2-amino-4-methyl-5-ethylpyrimidine 2-amino-4,6-diphenylpyrimidine 2-amino-4,6-dipropoxypyrimidine 2-amino-4-chloro-6-methylpyrimidine 2-amino-4,6-dichloropyrimidine 2-amino-4,6-dimethylpyrimidine Thus, the group A can be the residue of a pyridine, a quinoline, or a pyrimidine which carried a primary amino nitrogen in the 2-position at the start.

In the preparation of these new compounds, it is convenient usually to use at least a mole excess of 2-aminopyridine in order that the excess may act as an acid acceptor.

- to cool to room temperature.

Alternatively, another acid accepting. compound may be used as the solvent, for example, dimethyl aniline, or another acid acceptor may be added to the reaction mixture, such .as sodium carbonate, calcium carbonate, and the like.

My inventionrmay be further illustrated by the following examples in which parts are by weight unless otherwise specified.

Example] A mixture of 24.6 parts of chloranil, 37.6 parts of 2- s V and 130 parts of ethanol'is heated at the reflux temperature with stirring until thereac'tion is subtantially complete. The mixture is then cooled in an icebath. The solid material which forms is removed by aminopyridine filtration and washed thoroughly withalcohol. Recrystallization of the crude, product from nitrobenzene gives the pure reddish-brown quinone.

Example z 7 a A mixture of 12.3 parts of chloranil,"22.6rparts of 2- aminO-S-methyIpyridine and 80 parts of ethanol is heated with stirring at the reflux temperature until the reaction The mixture is then allowed The solid which precipitates is removed by filtration. Q-Recrystallization from is substantially complete.

nitrobenzene gives the pure cinnamon brown colored quinone, which dyes cotton, a reddish yellow shade from aclaretvat.

Similarly, if 2-amin0-3-methylpyridine,t2-amino-4,6- dimethylpyridine, 2-amino-4-bromopyridin'e, or 2-,amino- 6-ethoxypyridine are .used in equivalent quantities, the correspondingly substituted product is obtained.

Exampled' I i A 'mixture of 1 part of the product of Example 2, 3 parts of sodium hydrosulfite andlOOpzirts of water containing 10 parts of 24% sodiumhydroxidesolution, is heated at 140 F. for 20 minutes. The mixture is then diluted with 200 parts of water at 140 F.,' and a skein of cotton is immersed inth e dye'bath. After remaining in the bath 45 minutes at' this temperature, the skein is removed, air-oxidized, soaped, rinsed and dried. The cotton is dyed reddish yellow.

Example 4 The procedure of Example 2 is followed using an equivalent quantity of Lamino-S-chloropyridine in place of the aminomethylpyridine. Similarly, 2-amino-5- bromopyridine and 2-amino-5-iodopy dine give the corresponding bromo and iodo;compounds. I

' acid groups.

4 Example 5 om N N\ N /-NOI Example 6 The product of Example 5 is added slowlyto a refluxing solution of 5% sodium sulfide. The solid product is isolated by filtration.

The diamine can be diazotized and the amino group replaced by cyano, using the Sandmeyer reaction, after which the cyano groups can be hydrolyzed by dilute'acid to carboxamido groups and by dilute alkali to carboxylic Similarly, the Sandmeyer reaction can be used to replace the amino groups with mercapto groupstthrough the xanthatc) which can be alkylated to'alkylsulfides (e.g., dimethyl sulfate gives methylmercapto-which can be oxidized to methyl sulfonyl) or can be oxidized with I strong oxidizing agents to sulfonic acid groups.

Example 7 The procedure of Example 1 is followed using an equivalent quantity of Z-amino-quinoline in'place of the Z-aminopyridine, to give the above product. Similarly, the use of an equivalent quantity of 2-amino-8-ethoxyquinoline, 2-amino-3-phenylquinoline, or 2-amino- 6-' methoxy-S-phenylquinoline gives the 'correspondingly substituted products.

Example 8 (\N N N The procedure of Example 1 is followed using an equivalent quantity of Z-aminopyrimidine in place of the Z-aminopyridine. When 2-amino-4-methylpyrimidine, 2- amino 5 chloro 4,6 dimethylpyrimidine, 2 amino: S-chloropyrimidine, 2-amino-4,6-diiodopyrimidine, or 2- amino-4,6-diphenylpyrimidine is used instead, the correspondingly substituted product is obtained.

5 I claim: 1. A compound of the formula N 0% f N in which n is selected from the group consisting of O, 1 and 2 and in which R is selected from the group consisting of lower alkyl, lower alkoxy, chloro, bromo, iodo, phenyl, nitro, amino, cyano, earboxamiclo, carboxy, sulfo and mercapto.

2. A compound of the formula in which n is selected from the group consisting of 0, 1, and 2 and in which R is selected from the group consisting of lower alkyl, lower alkoxy, chloro, bromo, iodo, phenyl, nitro, amino, cyano, carboxarnido, carboxy, sulfo, and mercapto.

3. A compound of the formula in which n is selected from the group consisting of 0, l and 2 and in which R is selected from the group consisting of lower alkyl, lower alkoxy and phenyl.

4. A compound of the formula l? u; l il \N/ H L\ in which n is selected from the group consisting of O, 1 and 2 and in which R is selected from the group consisting of lower alkyl, lower alkoxy and phenyl.

5. A compound of the formula 6 in which n is selected from the group consisting of 0, 1, 2 and 3 and in which R is selected from the group consisting of lower alkyl, lower alkoxy, phenyl, chloro and iodo.

6. A compound of the formula N N'\ N\ n i Y (R) N N N in which n is selected from the group consisting of 0, 1, 2 and 3 and in which R is selected from the group consisting of lower alkyl, lower alkoxy, phenyl, chloro and iodo.

7. The compound:

8. The compound:

9. The compound:

om /\N 10. The compound:

0 II N N No references cited. 

5. A COMPOUND OF THE FORMULA 